Do they actually check part numbers on the turbine/compressor housings for that stuff? How do they know that it's a stock-looking TD04-13L vs. a TD05-16G, especially if you manage to hide it under a modified stock turbo heatshield ?

Hell, I've got a billet wheel 20G in a "stock" JDM GC8 16G housing... Never had a question about it at the VA inspection... They did not even notice my 45 mm EWG either...